Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 86-90).

Thesis (Ph. D.)--University of Wisconsin, 1965. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliography.

Thesis (M.S.)--Wisconsin. / Includes bibliographical references (leaves 66-69).

Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 58-59).

Typescript, etc.

A study of productivity and environment of forest plant communities was carried out in a selected area of the Coastal western hemlock zone. This study is a part of the composite ecological project on this zone, which includes investigations of soils and vegetation by George Lesko and Laszlo Orloci respectively. In the present investigation, climate, site productivity and environmental characteristics of the associations were statistically evaluated using correlation and regression analyses. The purpose of the study was to assess the degree to which the productivity and the plant community are influenced by individual environmental factors as well as by groups of factors. It was found that almost all the stands investigated were severely affected by fire and that most stands in lower altitudes have developed following destruction of the previous stands by fires. The history of major fires was traced back at least 500 years. The pattern of ecosystem forest communities has been used as a basis for the separation of biologically equivalent forest habitats. Microclimates of seven of the most important associations were studied in detail over a period of twelve months. It was concluded that topography is the primary factor influencing soil and water conditions within a given macroclimatic region. This results in the development of a certain microclimate and an accompanying association. The greatest differences among the plant communities were in temperature maxima and relative-humidity minima. Temperature means and minima, humidity means and maxima and rainfall all differed substantially only between the two subzones. Forest stand statistics were compared with conventional stand tables. Site-index curves for Douglas-fir, western hemlock, western red cedar, amabilis fir and Sitka spruce indicate differences between associations, and show typical trends which reflect site quality. It was concluded that a set of physiographic characteristics is typical for each association as well as for each productivity class. However, wide standard deviations and large overlaps indicate that similar physiographic locales may be occupied by different associations and by stands of different productivity. Topographical features were found to be more closely correlated with plant communities than with productivity. Many significant correlations between site index and sixteen environmental factors were found within individual associations. General trends in the site index - environmental factor relationships were also studied. The results of the investigations have shown that it is possible to use many combinations of environmental factors for an estimation of forest productivity and of plant community. However, it was found that, due to high correlations among environmental factors, only two or three characteristics need be used for estimation of either productivity or plant community with an accuracy approaching cases in which many environmental factors were considered. Almost all of the variability of the plant communities studied can be accounted for by differences in the soil and moisture regime. Similar correlation of site index with soil and moisture was found to be substantially lower. Seepage water and soil permeability were found to be the two most important characteristics of both plant community and site index. / Science, Faculty of / Botany, Department of / Graduate

The extent to which egg weight modifies genetic differences in body-weight of the embryo and chick and the correlation between embryonic growth rate and post-hatching growth rate were investigated. This was done by studying the relationships between (1) egg weight and body weight of embryo and chick; (2) strain and body weight of embryo and chick; (3) strain and percentage growth rate of embryo and chick; and (4) the relationship between embryonic growth rate and post-hatching growth rate. This study was conducted on five strains and one strain-cross. Two of the strains were bred for meat, (White Plymouth Rock and White Cornish); two were bred for high egg production, (White Leghorns); and one was an intermediate type, (White New Hampshire). The strain-cross was derived from mating males of one White Leghorn strain with females of the other. Individual egg weights were recorded for over 2,200 eggs. Between nine and eighteen embryos of each category were weighed from each of two incubators from the ninth to the eighteenth day of incubation. Between fifteen and thirty-three chicks of each category were weighed at hatching and at weekly intervals for three weeks. Analyses of variance of embryonic weights, chick weights, and embryonic or chick weights expressed as percentages of egg weight were done. Analyses of variance were also done on embryonic and post-hatching growth rates. Coefficients of correlation (r) between egg weight and embryonic or chick weight and also coefficients of regression of chick weight on egg weight were computed. The correlation between embryonic and post-hatching growth rates was estimated. From the results of the above tests it was concluded that: (1) Differences in embryonic weights among the strains were due to differences in inherent genetic factors; (2) Egg weight exerted a temporary measurable influence on embryonic and chick weight, the effect being greatest at hatching; (3) Differences in post-hatching growth rate among the strains were probably due to differences in nutritional factors which contributed to a more efficient utilization of nutrients by the heavy type chicks; and (4) Approximately 65 per cent of the variation in post-hatching growth rate to three weeks of age was dependent on the variation in growth rate during the nine- to fourteen-day incubation period. The estimate of correlation between growth rate during these two periods was, however, not precise. / Land and Food Systems, Faculty of / Graduate

Nine purebred Hereford bulls which had been tested for rate and efficiency of gain at the University of British Columbia, were bred to 99 heifers, 11 heifers to each bull, obtained from commercial breeders. Bach of the offspring, a total of 84, was weaned at 400 pounds and then placed on an individual feeding test, using the same feeding schedule and the same concentrate ration as that used for the bulls. At 800 pounds, the animals were slaughtered, rail graded and several carcass measurements were collected. Daily rate of gain and feed efficiency were computed over three periods. The following correlations were calculated: birth weight and daily gain during pre-weaning period; birth weight and daily gain during post-weaning period; daily gain during pre-weaning and post-weaning period; daily gain during post-weaning period and percentage lean in ribcut; daily gain during post-weaning period and carcass grade. The "r" value of each of the above calculations was found to be "low". There was a very high correlation between rate and efficiency of gain for each of the three periods: 400 - 800 pounds, r = -0.98 400 - 600 pounds, r = -0.97 600 - 800 pounds, r = -0.98 A simple plan for home testing was outlined. This plan calls for selection on the basis of rate of gain during a test period of approximately 5 months. Animals enter the test period in groups with equal body weight and are full fed. / Land and Food Systems, Faculty of / Graduate

The effects of 12°, 13°, 24° and 30°C temperatures; 24, 20, 16 and 12 hour photoperiods; 2000 and 500 ft.-c. light intensities and light high and low in far-red energy on numbers of florets and percent sterility per head and per plant were studied on combinations of seventeen barley varieties. Numbers of florets per head and per plant were reduced with an increase in temperature. Numbers of florets were increased with a decrease in photoperiod at low, but not at high, temperature. At the low light intensity there was a slight decrease in number of florets per head and a pronounced reduction in tillering. The virtual absence of far-red energy had no effect on tillering, but caused a significant increase in number of florets per tiller head. Plant sterility was lowest at 18°C. Main head sterility was low at 12° and 18°C but was markedly increased at 24° and 30°C. Tiller head sterility was much higher than that of main heads at all temperatures and was as high at 12°C as at 24°C. Photoperiod had little effect on main head sterility except for causing a marked increase at 12 hour. At the optimum temperature for development (13°C), intermediate photoperiods had the lowest plant sterility. The reduction in light intensity caused a 30 percent increase in plant percent sterility. Light low in far-red energy caused an average increase of 25 percent in plant sterility. Varieties had significant interactions with temperature, photoperiod, light intensity, and light quality in determining the numbers of florets differentiated per head and per plant. Temperature and light intensity were the only factors to interact with variety for percent sterility. The varieties Aria, Asa, Betzes, O.A.C. 21, Palliser, Pirkka, Titan, Trebi, and Vantage were especially sensitive to the stress conditions imposed. / Land and Food Systems, Faculty of / Graduate

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